It occurs to me that there are two related by separate ways to disrupt elections:
Note that you can do #2 without having done #1.
With this coming US election, there is mounting evidence that Russia is trying to do #1, but the point of #2 is that they don’t have to be successful to…well, be successful.
If the election is close—which is looking decreasingly likely—convincing narrative that the election was compromised will produce almost all the value of actually hacking it, reversing the outcome to favor you, and having it go unnoticed.
To put these in order:
There are other options, and these may change in value based on your goals, tactics, and strategy. But what’s important to understand is that when the integrity of something is of value, and you’re not able to actually affect its integrity, you can still achieve results by successfully raising questions of its legitimacy.
If the election is anywhere near close, expect to see all sorts of evidence of #1, #2, and/or both.